Cyclic (Alkyl)amino Carbene Complex of Aluminum(III) in Catalytic Guanylation Reaction of Carbodiimides

Herein we report the synthesis of a cyclic (alkyl)­amino carbene (cAAC) complex of AlMe3. This complex was used as an efficient catalyst for the guanyl­ation reaction of carbo­diimides with primary aryl­amines and secondary amines to deliver guanidine derivatives in good to excellent yields. This catalytic protocol can tolerate a wide range of functional groups. Furthermore, the longevity of the catalyst was tested in successive catalytic cycles, which indicated a sustained catalytic activity over a multiple cycles. The mechanistic pathway was well understood with the help of stoichiometric reaction and DFT study.